scholarly journals Fibroblast growth factor is predicted to dominate MAPK activation by pro-angiogenic factors

2018 ◽  
Author(s):  
Min Song ◽  
Stacey D. Finley

AbstractAngiogenesis is important in physiological and pathological conditions, as blood vessels provide nutrients and oxygen needed for tissue growth and survival. Therefore, targeting angiogenesis is a prominent strategy in both tissue engineering and cancer treatment. However, not all of the approaches to promote or inhibit angiogenesis lead to successful outcomes. Angiogenesis-based therapies primarily target pro-angiogenic factors such as vascular endothelial growth factor-A (VEGF) or fibroblast growth factor (FGF) in isolation, and there is a limited understanding of how these promoters combine together to stimulate angiogenesis. Thus, more quantitative insight is needed to understand their interactions. In this study, we have trained and validated a detailed mathematical model to quantitatively characterize the crosstalk of FGF and VEGF intracellular signaling. The model focuses on FGF- and VEGF-induced mitogen-activated protein kinase (MAPK) signaling and phosphorylation of extracellular regulated kinase (ERK), which promote cell proliferation. We apply the model to predict the dynamics of phosphorylated ERK (pERK) in response to the stimulation by FGF and VEGF individually and in combination. The model predicts that FGF plays a dominant role in promoting ERK phosphorylation, compared to VEGF. The modeling predictions show that VEGFR2 density and trafficking parameters significantly influence the level of VEGF-induced pERK. The model matches experimental data and is a framework to synthesize and quantitatively explain experimental studies. Ultimately, the model provides mechanistic insight into FGF and VEGF interactions needed to identify potential targets for pro-or anti-angiogenic therapies.

Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1099
Author(s):  
Pedro Pinto-Bravo ◽  
Maria Rosa Rebordão ◽  
Ana Amaral ◽  
Carina Fernandes ◽  
António Galvão ◽  
...  

The oviduct presents the ideal conditions for fertilization and early embryonic development. In this study, (i) vascularization pattern; (ii) microvascular density; (iii) transcripts of angiogenic factors (FGF1, FGF2, VEGF) and their receptors—FGFR1, FGFR2, KDR, respectively, and (iv) the relative protein abundance of those receptors were assessed in cyclic mares’ oviducts. The oviductal artery, arterioles and their ramifications, viewed by means of vascular injection-corrosion, differed in the infundibulum, ampulla and isthmus. The isthmus, immunostained with CD31, presented the largest vascular area and the highest number of vascular structures in the follicular phase. Transcripts (qPCR) and relative protein abundance (Western blot) of angiogenic factors fibroblast growth factor 1 (FGF1) and 2 (FGF2) and vascular endothelial growth factor (VEGF), and their respective receptors (FGFR1, FGFR2, VEGFR2 = KDR), were present in all oviduct portions throughout the estrous cycle. Upregulation of the transcripts of angiogenic receptors FGF1 and FGFR1 in the ampulla and isthmus and of FGF2 and KDR in the isthmus were noted. Furthermore, in the isthmus, the relative protein abundance of FGFR1 and KDR was the highest. This study shows that the equine oviduct presents differences in microvascular density in its three portions. The angiogenic factors VEGF, FGF1, FGF2 and their respective receptors are expressed in all studied regions of the mare oviduct, in agreement with microvascular patterns.


2015 ◽  
Vol 112 (40) ◽  
pp. 12528-12533 ◽  
Author(s):  
Hassan Musa ◽  
Crystal F. Kline ◽  
Amy C. Sturm ◽  
Nathaniel Murphy ◽  
Sara Adelman ◽  
...  

Nav channels are essential for metazoan membrane depolarization, and Nav channel dysfunction is directly linked with epilepsy, ataxia, pain, arrhythmia, myotonia, and irritable bowel syndrome. Human Nav channelopathies are primarily caused by variants that directly affect Nav channel permeability or gating. However, a new class of human Nav channelopathies has emerged based on channel variants that alter regulation by intracellular signaling or cytoskeletal proteins. Fibroblast growth factor homologous factors (FHFs) are a family of intracellular signaling proteins linked with Nav channel regulation in neurons and myocytes. However, to date, there is surprisingly little evidence linking Nav channel gene variants with FHFs and human disease. Here, we provide, to our knowledge, the first evidence that mutations in SCN5A (encodes primary cardiac Nav channel Nav1.5) that alter FHF binding result in human cardiovascular disease. We describe a five*generation kindred with a history of atrial and ventricular arrhythmias, cardiac arrest, and sudden cardiac death. Affected family members harbor a novel SCN5A variant resulting in p.H1849R. p.H1849R is localized in the central binding core on Nav1.5 for FHFs. Consistent with these data, Nav1.5 p.H1849R affected interaction with FHFs. Further, electrophysiological analysis identified Nav1.5 p.H1849R as a gain-of-function for INa by altering steady-state inactivation and slowing the rate of Nav1.5 inactivation. In line with these data and consistent with human cardiac phenotypes, myocytes expressing Nav1.5 p.H1849R displayed prolonged action potential duration and arrhythmogenic afterdepolarizations. Together, these findings identify a previously unexplored mechanism for human Nav channelopathy based on altered Nav1.5 association with FHF proteins.


2004 ◽  
Vol 24 (13) ◽  
pp. 5657-5666 ◽  
Author(s):  
Betty Lamothe ◽  
Masashi Yamada ◽  
Ute Schaeper ◽  
Walter Birchmeier ◽  
Irit Lax ◽  
...  

ABSTRACT The docking protein Gab1 has been implicated as a mediator of multiple signaling pathways that are activated by a variety of receptor tyrosine kinases and cytokines. We have previously proposed that fibroblast growth factor 1 (FGF1) stimulation of tyrosine phosphorylation of Gab1 and recruitment of phosphatidylinositol (PI) 3-kinase are mediated by an indirect mechanism in which the docking protein fibroblast receptor substrate 2α (FRS2α) plays a critical role. In this report, we explore the role of Gab1 in FGF1 signaling by using mouse embryo fibroblasts (MEFs) derived from Gab1−/− or FRS2α−/− mice. We demonstrate that Gab1 is essential for FGF1 stimulation of both PI 3-kinase and the antiapoptotic protein kinase Akt, while FGF1-induced mitogen-activated protein kinase (MAPK) stimulation is not affected by Gab1 deficiency. To test the indirect mechanism for FGF1 stimulation of PI 3-kinase and Akt, we use a chimeric docking protein composed of the membrane targeting signal and the phosphotyrosine-binding domain of FRS2α fused to the C-terminal portion of Gab1, the region including the binding sites for the complement of signaling proteins that are recruited by Gab1. We demonstrate that expression of the chimeric docking protein in Gab1−/− MEFs rescues PI 3-kinase and the Akt responses, while expression of the chimeric docking protein in FRS2α−/− MEFs rescues stimulation of both Akt and MAPK. These experiments underscore the essential role of Gab1 in FGF1 stimulation of the PI 3-kinase/Akt signaling pathway and provide further support for the indirect mechanism for FGF1 stimulation of PI 3-kinase involving regulated assembly of a multiprotein complex.


Hypertension ◽  
2000 ◽  
Vol 36 (suppl_1) ◽  
pp. 683-683
Author(s):  
Corinne Pellieux ◽  
Alessandro Foletti ◽  
Thercse Sauthier ◽  
Aubert Jean-Francois ◽  
Beermann Friedrich ◽  
...  

29 In renovascular hypertension, angiotensin II leads to an elevation of blood pressure and to cardiac hypertrophy. The fibroblast growth factor-2 (FGF-2) has been implicated in cardiomyocyte growth. Therefore, we investigated whether FGF-2 could control the development of angiotensin II-induced cardiac hypertrophy. Mice deficient for the expression of FGF-2 were created, and the role of FGF-2 was investigated in the two kidney-one clip (2K1C) model of renin-dependent hypertension. The activation of the MAPK pathways were shown to be crucial in the intracellular signaling leading to cardiac hypertrophy. Therefore, we followed also the cardiac activation of JNK, ERK and the p38 kinase in these animals. Both wild-type and FGF-2 deficient (FGF-2 -/-) mice showed similar elevation of blood pressure in the 2K1C model. Interestingly, 2K1C FGF-2 -/- mice developed markedly reduced hypertrophy as compared to wild-types. Moreover, in 2K1C wild-types, cardiac hypertrophy developed in association with a concomitant stimulation of JNK, ERK and p38. In contrast, JNK activation was strongly decreased in hypertensive mice deficient for FGF-2, while p38 and ERK were less affected. These data suggest that FGF-2 is important in mediating angiotensin II-induced cardiac hypertrophy in renovascular hypertension via autocrine/paracrine mechanisms.


2006 ◽  
Vol 18 (2) ◽  
pp. 182
Author(s):  
P. P. Borowicz ◽  
D. A. Redmer ◽  
A. T. Grazul-Bilska ◽  
G. Ptak ◽  
P. Loi ◽  
...  

Embryonic losses are high in mammals, with more than 30% of fertilized eggs not resulting in an offspring. The development of the placenta is critical for normal fetal growth and development as it provides for exchange of respiratory gases, nutrients, and wastes between the fetal and maternal systems. Placental vascular development determines the rate of placental blood flow, which is a primary determinant of placental function. Recent studies suggest that vascular endothelial growth factor (VEGF), its receptors (VEGFR), along with angiopoietins (Ang-1 and Ang-2) and their common receptor Tie-2, are major placental angiogenic factors, along with fibroblast growth factor-2 (FGF-2) and its receptor (FGFR). To evaluate the patterns of placental expression of these factors during early placental development, gravid uteri were obtained from ewes (n = 6 per day) on Days 12, 18, 24, 30, and 40 of gestation (day of mating = Day 0). At slaughter the uterine and embryonic tissues were weighed and representative samples of utero-placenta (CAR - caruncle, maternal placenta; ICAR - intracarunclar, endometrium; FM, fetal membranes) were snap frozen on dry ice and analyzed for relative mRNA levels by real-time RT-PCR (ABI Prism 7000, Sequence Detection System, Applied Biosystems, Monza, Italy) of vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor-1 (VEGFR-1), vascular endothelial growth factor receptor-2 (VEGFR-2), angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2), receptor for both angiopoietins (Tie-2), fibroblast growth factor-2 (FGF-2), and fibroblast growth factor receptor (FGFR). The data were analyzed by nonlinear procedures using proc reg of SAS (SAS Institute, Inc., Cary, NC, USA). In CAR, the data showed the exponential increase from Days 12 to 40 in mRNA expression for VEGFR-1 (P < 0.0004; 0.04398e0.08794�day), VEGFR-2 (P < 0.01; 0.119208e0.06537�day), Ang-1 (P < 0.005; 0.00488e0.10881�day), Ang-2 (P < 0.0001; 0.01591e0.07864�day), Tie-2 (P < 0.03; 0.00488e0.06852�day), and FGFR (P < 0.08; 0.24577e0.04721�day). In the CAR, we also observed an exponential decrease in mRNA concentration for VEGF (P < 0.05; 28.193e-1.0719�day). In ICAR, we observed an exponential increase in mRNA concentration for VEGF (P < 0.05; 1.11685e0.06865�day), VEGFR-1 (P < 0.07; 0.09853e0.0383�day), Ang-1 (P < 0.09; 0.009318e0.05711�day), and Ang-2 (P < 0.004; 0.012647e0.09973�day). For FM, no changes in mRNA levels were observed from Days 12 to 40, but levels of all mRNAs were similar to those in CAR and ICAR. Based on the patterns of mRNA expression, these data indicate that these angiogenic factors may play an important role in early placental angiogenesis in sheep. This work was supported by NIH grant HL64141 to LPR and DAR.


2001 ◽  
Vol 281 (4) ◽  
pp. L766-L775 ◽  
Author(s):  
Isabel Carreras ◽  
Celeste B. Rich ◽  
Julie A. Jaworski ◽  
Sandra J. Dicamillo ◽  
Mikhail P. Panchenko ◽  
...  

Previously, we have demonstrated that basic fibroblast growth factor (bFGF) decreases elastin gene transcription in confluent rat lung fibroblasts via the binding of a Fra-1-c-Jun heterodimer to an activator protein-1-cAMP response element in the distal region of the elastin promoter. In the present study, we show that bFGF activates the mitogen-activated protein kinase extracellular signal-regulated kinase 1/2, resulting in the translocation of phosphorylated extracellular signal-regulated kinase 1/2 into the nucleus followed by increased binding of Elk-1 to the serum response element of the c-Fos promoter, transient induction of c-Fos mRNA, and sustained induction of Fra-1 mRNA. The addition of PD-98059, an inhibitor of mitogen-activated protein kinase kinase, abrogates the bFGF-dependent repression of elastin mRNA expression. Comparative analyses of confluent and subconfluent fibroblast cultures reveal significant differences in elastin mRNA levels and activator protein-1 protein factors involved in the regulation of elastin transcription. These findings suggest that bFGF modulates specific cellular events that are dependent on the state of the cell and provide a rationale for the differential responses that can be expected in development and injury or repair situations.


2001 ◽  
Vol 21 (23) ◽  
pp. 8104-8116 ◽  
Author(s):  
Jennifer L. Schutzman ◽  
Christina Z. Borland ◽  
John C. Newman ◽  
Matthew K. Robinson ◽  
Michelle Kokel ◽  
...  

ABSTRACT EGL-15 is a fibroblast growth factor receptor in the nematodeCaenorhabditis elegans. Components that mediate EGL-15 signaling have been identified via mutations that confer a Clear (Clr) phenotype, indicative of hyperactivity of this pathway, or a suppressor-of-Clr (Soc) phenotype, indicative of reduced pathway activity. We have isolated a gain-of-function allele of let-60 ras that confers a Clr phenotype and implicated bothlet-60 ras and components of a mitogen-activated protein kinase cascade in EGL-15 signaling by their Soc phenotype. Epistasis analysis indicates that the gene soc-1 functions in EGL-15 signaling by acting either upstream of or independently of LET-60 RAS. soc-1 encodes a multisubstrate adaptor protein with an amino-terminal pleckstrin homology domain that is structurally similar to the DOS protein in Drosophilaand mammalian GAB1. DOS is known to act with the cytoplasmic tyrosine phosphatase Corkscrew (CSW) in signaling pathways inDrosophila. Similarly, the C. elegans CSW ortholog PTP-2 was found to be involved in EGL-15 signaling. Structure-function analysis of SOC-1 and phenotypic analysis of single and double mutants are consistent with a model in which SOC-1 and PTP-2 act together in a pathway downstream of EGL-15 and the Src homology domain 2 (SH2)/SH3-adaptor protein SEM-5/GRB2 contributes to SOC-1-independent activities of EGL-15.


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